As conventional methods of inspecting crystallinity of a surface of a sample, such as a semiconductor substrate of an integrated circuit device and so on, there are known a low energy electron diffraction (LEED) method and a reflection high energy electron diffraction (RHEED) method, both of which use electron ray or beam, and there is also known a small incident angle X-ray diffraction method which uses X-ray. In each of these methods, electron beam or X-ray is irradiated onto a sample, and a diffraction pattern of scattered electron beam or X-ray is detected to inspect crystallinity of a sample surface. Also, in order to estimate crystallinity of a local area of a sample, there are known a method of performing electron diffraction measurement by using converged electron beam, and a method by using a scanning tunneling microscope which uses a probe.
In a recent semiconductor device having a very high integration degree, it is often required to form a narrow and deep hole in a vertical direction on the surface of a semiconductor element, during a manufacturing process thereof. However, when an aspect ratio of such hole is very large, an analysis of the bottom area of such hole was impossible. This is because, in the conventional diffraction method using electron beam or X-ray, a direction of incidence of electron beam or X-ray onto the surface of a sample and a direction of emanation of detected electrons or X-ray are limited. Also, in the observation method by a scanning tunneling microscope which uses a probe, it was difficult to insert the probe into such hole, and, therefore, an analysis of the bottom area of such hole was difficult because of the structural limitation of the microscope.